Effects Of Different Graphene Oxides On The Performance Of Negative Plates And Lead-Acid Batteries

The traditional lead-acid battery under the high-rate partial charge?HRPSoC?working condition will accumulate a large amount of lead sulfate crystals on the surface of the negative plate in a short time,resulting in irreversible sulfation of the negative plate and greatly shortened cycle life.Introduction of carbon material into the active material of the negative plate?NAM?can solve this problem.However,the addition of carbon material to the negative plate brings a serious hydrogen evolution problem.Our research group previously reported that graphene oxide?GO?-based composites can greatly improve the HRPSoC cycle life,and carbon black?CB?with suitable surface functional groups can suppress the hydrogen evolution of the negative plate,but the mechanism remains unclear.In this dissertation,we prepared different kinds of GO with various surface oxidation functional groups and studied their effects on the negative plates of lead-acid batteries.Based on this research,the main findings are as follows:1.Preparation and characterization of different types of GO/P-RGO Considering the influence of the content of oxidation functional groups,six kinds of GO/P-RGO materials with different oxidation degrees were obtained?oxidation degree range from 58.90%to 23.26%?.Taking into account the influence of the type of oxidation functional groups,GO-M with high C–O?C–OH and C–O–C?ratios was prepared by addition of distilled water,while GO4-H with high C=O,O–C=O ratio and low C–O ratio was obtained through high-temperature reaction.2.Effect of oxidation degree of GO on lead-acid battery The addition of as-prepared GO with different oxidation degrees into negative plates greatly promotes the evolution of H₂ and the reduction of PbSO₄,which also reduces the reaction resistance and promotes the reduction of lead sulfate.Negative plates show greater specific surface areas,pore volume and hydrophilicity after addition of GO composites.The negative plate with M-GO(highest oxidation degree,S_CO/S_C-Total=58.9%)shows the most suitable electrochemical and physical properties.The irreversible sulfation phenomenon is suppressed,and the battery possesses a better HRPSoC cycle life with35598 cycles.Changing the content of M-GO additive added to the negative plate?0.0%-2.0%?,the result shows that 1.0%is the most suitable additive content.3.Effect of type of oxidation functional groups of GO on lead-acid battery The addition of as-prepared four kinds of GO with different ratios of oxidation functional groups greatly promotes the evolution of H₂ and the reduction of PbSO₄,in which the relative higher content of C–O?C–OH and C–O–C?shows a strong promotion of H₂ evolution.The negative plate containing GO4-H?higher proportion of C=O and O–C=O?shows suitable electrochemical and physical properties.The battery shows a better HRPSoC cycle life with 19672 cycles.At the same oxidation degree,GO with a lower content of C–O and a higher content of C=O and O–C=O?eg,GO4-H and R-GO1?are more suitable as additives for negative plates in lead-acid batteries during HRPSoC modes.